The Tanikaip Purānam gives the description of the Kārttikeya form. Murukan has six faces and six hands, of the left three hands, one is in the varada mudrā and in the other two hands he bears the thrunderbolt and shield. Of the three right hands, one is in the abhaya mudrā and in the other two hands he bears the spear (Vel) and the sceptre (cenkkōl). Those who concentrate upon this aspect will be relieved of all diseases. This form of Murukan is shaped to represent Kārttikeya.
At Adi Kumbeshwarar Kovil in Kumbakonam, Kārttikeya shines with six faces and six hands.36 In four hands, he has the japa māla, sword, thunderbolt and shield; the right hand is in the abhaya pose and the left is bent.
From "In the Footsteps of Saint Arunagirinathar: Pilgrimage to the sacred places in the Tiruppukal" by Vallayapettai Ra. Krishnan